This invention relates to a vehicle suspension device for use in vehicles such as passenger cars, trucks or the like and, particularly to a vehicle suspension device of the type including a hydraulic damper including a cylinder and a piston rod extending outwardly of the cylinder through one end of the cylinder, and an air spring unit including a flexible tubular wall member and receiving therein pressurized gas such as air.
Conventionally, the flexible tubular wall member has an inner tubular wall portion the free end of which is directly secured to the cylinder of the hydraulic damper, an outer tubular wall portion surrounding at least a part of the inner tubular wall and the free end of which is secured to a skirt portion of a cup-shaped member secured to the extending end of the piston rod, and a rolling wall portion formed between the outer and inner wall portions. However, in securing the inner wall portion of the tubular wall member to the outer circumference of the cylinder of the hydraulic damper, the cylinder will be deformed, thereby impairing the function of the hydraulic damper. Further, the tubular wall member is sometimes secured to the cylinder and the cup-shaped member in a twisted condition with respect to the longitudinal axis, thereby impairing the durability of the tubular wall member. Further, in some cases, the free end of the inner wall portion of the tubular wall member is secured to a reduced diameter upper end portion of the cylinder, and the tubular wall member extends along the outer surface of the cylinder which inclines relative to the longitudinal axis of the cylinder, thereby impeding the smooth rolling movement of the tubular wall member.